A rashguard shirt is simply the most well constructed, lycra based, UV protective shirt available. Worn for years by surfers and water sports enthusiasts, these shirts are an excellent replacement for sunscreen, which makes them invaluable to parents and beachgoers everywhere. SIZING CHART 6-S 20-30 lbs 8-M 30-45 lbs 10-L 50-65 lbs 12-XL 65-80 lbs IF IN DOUBT GO LARGER